Comparison of Midline and Paramedian Approaches in Coccygectomy

Introduction

Coccygodynia is pain localized to the coccyx or perianal sacral region, which is typically exacerbated by prolonged sitting or by rising from a seated position, and can significantly impair quality of life [1]. It is reported to be approximately 5 times more common in women than in men and can negatively affect daily activities, social life, and even work capacity [2,3]. In some cases, the pain can intensify during sexual activity or defecation [2].

Conservative management is considered the first-line approach and typically includes ergonomic cushions, non-steroidal anti-inflammatory drugs, physical therapy, and local steroid or anesthetic injections, when indicated [4,5]. Most patients achieve adequate relief with these measures; however, those with persistent symptoms for 6 months or longer, despite structured conservative management, are generally considered to have refractory coccygodynia [4,6]. In such refractory cases, coccygectomy can be indicated. Coccygectomy has been reported to yield successful outcomes in up to 90% of patients [6]. Nevertheless, the close anatomical relationship of the coccyx to the rectum raises concerns regarding potential complications such as infection, wound dehiscence, and rectal perforation [7,8].

Traditionally, coccygectomy has been performed through a standard midline incision [9]. However, complication rates as high as 30% have been reported with this technique [10], prompting the development of alternative approaches. One such method is the paramedian approach, in which the incision is made 0.5 to 1.5 cm lateral to the midline. This technique has been associated with lower wound-related complication rates, compared with the classical midline approach [11–13]. However, the comparative outcomes of paramedian versus midline approaches remain insufficiently studied in the current literature.

The aim of the present study is to compare the clinical outcomes of patients undergoing coccygectomy via either the paramedian or the standard midline approach. Specifically, we sought to evaluate wound-related complications, bleeding, and infection rates. We hypothesize that the paramedian approach may be associated with fewer complications and better clinical outcomes. By addressing this issue, our study aims to provide clinically relevant evidence to guide surgical decision-making in the management of coccygodynia.

Material and Methods

STUDY DESIGN AND ETHICS:

This was a retrospective study. Patient data were collected after obtaining approval from the institutional clinical research ethics committee (Decision No: 411). All patients were treated in a single tertiary care center. Patient confidentiality and privacy were strictly protected throughout the study, and all data were anonymized prior to analysis. The authors declare no conflicts of interest.

STUDY GROUP:

A total of 54 patients who underwent coccygectomy for chronic coccygodynia between January 2015 and December 2023 were initially reviewed. The sample size of 41 patients was determined based on inclusion/exclusion criteria to ensure adequate statistical power to detect differences between groups. Thirteen patients were excluded due to irregular follow-up, incomplete medical records, a history of tumors or infections in the sacrococcygeal region, prior surgery in the same area (eg, pilonidal sinus surgery), or being under 18 or over 60 years of age. Consequently, 41 patients (32 women, 9 men) were included in the final analysis.

TREATMENT PROTOCOL:

All patients first underwent structured conservative management, including pharmacological treatment (primarily non-steroidal anti-inflammatory drugs), ergonomic sitting cushions, and lifestyle modifications for at least 3 months. Patients who did not achieve sufficient relief with these measures subsequently received ganglion impar block as an interventional pain management step. Only patients who failed to respond to conservative therapy and ganglion impar block were considered candidates for coccygectomy.

All patients were informed about the aim of the study in accordance with the principles of the Declaration of Helsinki, and written and/or verbal informed consent was obtained. No randomization or blinding was performed, due to the retrospective nature of the study, which is acknowledged as a limitation.

SURGICAL TECHNIQUE:

Patients were divided into 2 groups based on the surgical approach: those who underwent coccygectomy with a classical midline incision and those who underwent the procedure using a paramedian coccygeal incision. Preoperatively, all patients underwent dynamic coccygeal radiography to assess instability, with patients in both the seated and standing positions (Figure 1). Coccygeal subluxation or 25° or greater angulation difference between positions was considered hypermobility [14]. All operations were performed under general anesthesia with standard monitoring, including electrocardiogram, blood pressure, and pulse oximetry. Patients were placed in the prone position with appropriate padding to prevent pressure injuries.

In both groups, a 4 to 5 cm incision was made at the coccygeal level; in the paramedian group, the incision was positioned approximately 1.5 to 2 cm lateral to the midline (Figure 2). After electrocautery dissection through superficial and deep tissues, the coccyx was exposed. To protect the rectum, the coccyx was elevated with a bowel clamp, and electrocautery tips were bent to 80° to 90° for safety. The anterior surface of the coccyx was dissected subperiosteally from proximal to distal, ensuring rectal preservation, and the coccyx was excised (Figure 3).

Following hemostasis and fluoroscopic verification, the field was irrigated with saline, and incisions were closed in layers (Figure 4). The wound was dressed with sterile gauze. The postoperative protocol included covering the wound for 3 days, followed by leaving it open to allow for showering. Patients were instructed not to sit or lie supine for 2 weeks. Wound healing was assessed starting the second postoperative week, and sutures were removed at the end of that week. Follow-up visits were scheduled at 1, 3, and 6 months (Figure 5).

EVALUATED PARAMETERS:

Wound healing time, mechanical wound complications, surgical site infections (classified as superficial vs deep), and intraoperative bleeding were recorded. Visual analog scale (VAS) scores and Oswestry Disability Index (ODI) scores were recorded preoperatively and at 3-month and 6-month follow-ups. Complete recovery was defined as full wound closure, with a VAS score of 3 or less.

Intraoperative bleeding volume was calculated from aspirated blood and soaked gauze sponges (1 fully saturated gauze equals approximately 12 cc blood) [14]. VAS outcomes were categorized as excellent (≤2), good (≤3), satisfactory (≤6), and poor (>6) [15].

STATISTICAL ANALYSIS:

All analyses were performed using SPSS version 29. Continuous variables are expressed as mean±SD, and categorical variables as numbers and percentages. The independent t test or Mann-Whitney U test was used for continuous variables, and the chi-square or Fisher exact test for categorical variables. Missing data were handled using listwise deletion. Statistical significance was set at P<0.05.

Results

The mean age of the patients was 36.7 years (range, 18–50), and the mean follow-up duration was 2.3 years (range, 6 months to 4.5 years). The classical midline group included 18 patients (15 women, 3 men), and the paramedian group included 23 patients (17 women, 6 men). There were no statistically significant differences between the groups in terms of age, sex, body mass index, or follow-up time, indicating comparable baseline characteristics (Table 1). Fall-related trauma was the most common etiology in both groups, followed by idiopathic cases, prolonged sitting, birth-related trauma, and heavy lifting (Table 2). Coccygeal instability was observed in 10 patients in the midline group and 14 patients in the paramedian group.

Preoperative VAS scores were similar between the groups (P=0.255). At the 3-month follow-up, VAS scores were significantly lower in the paramedian group than the midline group (P=0.045), consistent with our hypothesis that the paramedian approach improves early postoperative pain. However, no significant difference was found at the last follow-up (P=0.139). ODI scores did not differ significantly between the groups preoperatively (P=0.989), at 3 months (P=0.095), or at 6 months (P=0.858), suggesting comparable long-term functional recovery in both groups (Table 3).

The mean time to complete recovery was 5.12 months in the midline group and 4.46 months in the paramedian group. Although the recovery period was shorter in the paramedian incision group, the difference did not reach statistical significance (P=0.101). In terms of operative time, the average was 52.2 minutes in the midline group and 50.9 minutes in the paramedian group (P=0.552). Mean intraoperative bleeding volume was 59.2 mL in the midline group and 53.7 mL in the paramedian group (P=0.124; Table 3).

Mechanical wound dehiscence occurred in 5 patients (27.8%) in the midline group, whereas no cases were observed in the paramedian group. This difference was statistically significant (P=0.01), directly supporting the hypothesis that the paramedian approach reduces wound-related complications. Postoperative wound infection occurred in 4 patients (22.2%) in the midline group and 1 patient (4.3%) in the paramedian group (P=0.169). Although not statistically significant, the infection rate was approximately 4 times higher in the midline group, indicating a trend toward fewer infections with the paramedian approach. One patient in the midline group developed pericoccygeal bursitis, which resolved with anti-inflammatory treatment. No rectal injuries or hernias were observed intraoperatively or during follow-up in either group.

Discussion

COMPLICATIONS:

The classical midline vertical incision remains the most widely used approach. However, because of anatomical tension in this region, postoperative wound complications are relatively frequent [21]. Reported complication rates range from 26% to 36% [10,22]. A meta-analysis of 21 studies on midline coccygectomy reported an overall complication rate of 11.4%, with 68.1% infection and 18.1% wound dehiscence [23]. Our results showed higher complication rates in the midline group, consistent with these values.

Andrea et al reported a wound infection rate of 4.7% with dual antibiotic prophylaxis [17]. Several studies recommend postoperative antibiotic prophylaxis for up to 48 hours [22,24,25]. In our series, patients received cefazolin prophylaxis, but the midline group still had higher infection rates, suggesting that the surgical approach may be more critical than the prophylaxis regimen. Alternative techniques, such as Z-plasty, have been proposed to reduce wound tension [11], although this method carries risks related to flap viability. By contrast, the paramedian approach avoids midline tension and in our study resulted in fewer complications, especially wound dehiscence (P=0.01).

In the paramedian group, only 1 patient developed a superficial wound infection, likely related to chemotherapy for cervical cancer, which impaired wound healing. No cases of wound dehiscence were recorded in this group. These findings reinforce that the paramedian approach reduces complications, even in high-risk patients.

LIMITATIONS AND STRENGTHS:

This study has several limitations. The retrospective design and relatively small sample size limit the generalizability of our findings. Moreover, the study did not include randomized allocation, potentially introducing selection bias. However, a key strength is that all surgeries were performed by a single surgeon at a single institution, ensuring a consistent surgical technique, perioperative care, and follow-up protocol. Future multicenter, prospective studies with larger cohorts are warranted to validate the advantages of the paramedian approach and to assess its potential integration into surgical guidelines.

Conclusions

In conclusion, the classical midline and paramedian incision techniques in coccygectomy offer similar long-term clinical outcomes. However, the paramedian approach was associated with significantly lower rates of wound dehiscence (P=0.01) and better early postoperative pain control (P=0.045). Although infection rates were lower in the paramedian group, the difference was not statistically significant. These findings suggest that the paramedian approach may provide short-term advantages in recovery, while overall outcomes converge in the longer term.

Given the retrospective design and small sample size of this study, the results should be interpreted with caution. Larger, prospective, multicenter trials are needed to validate these benefits. From a clinical standpoint, the paramedian incision may represent a promising option for reducing wound-related complications and improving early postoperative pain control in patients undergoing coccygectomy.